Method of producing metallic fastener blanks



1934- G. A. ANDERSON METHOD OF PRODUCING METALLIC FASTENER BLANKS Filed June so, 1932 iii/72261 6290/ 6 [Anderson .9%

Patented Jan. 2, 1934 Application June 30, 1932.

The present invention relates to an improved HCE METHOD OF PRODUCHNG METALLIC FASTENER ELANKS George A. Anderson, Worcester, Mass, assignor to United States Envelope Company, Springfield, Mesa, a corporation of Maine 4 Claims.

method of producing metallic blanks of a form adapted to be employed as fastenersfor envelopes.

The invention relates particularly to the 5 production of metallic blanks for envelope fastoners of the type shown in United States Letters above described type have been produced by punching them individually from sheet metal stock, with a considerable loss in scrap metal,

due to the irregular outlines of the blanks.

The

object of the present invention is to provide a method of producing such fastener blanks with a substantial reduction of waste resulting from the punching operations, whereby a material sa* ing is effected in the manufacture of fastener In the production envelopes in large quantities.

of fastener blanks according to the present invention, a series of blanks are cut at each operation of a multiple punch, with the direction and amount of feed of he stock between each punch stroke resulting in interlocking of the blanked areas to such an extent that waste is reduced to a minimum. The above and other advantageous features of the invention will hereinafter more fully appear from the following description with reference to the accompanying drawing,

in which Fig. 1 is a plan view illustrating the manner of feeding the sheet metal stock and the cutting of a series of fastener blanks therefrom by the first punch operation.

Fig. 2 shows the appearance of the stock after a number of punch operations.

Fig. 3 is a section through the cutting portions of a punch for producing the blanks.

Fig. i is a plan view of a die for cooperation with the punch of Fig. 3.

Fig. 5 shows a number of blanks as cut from the stock by an operation of the punch and die.

Fig. 6 is a fragmentary View illustrating interlocking of the blanked areas, on an enlarged scale.

Like reference characters refer to like parts in the diiferent figures.

Referring to Fig. 5, there is shown a number of fastener blanks A produced by the practice of the method of the present invention, each blank A consisting of a base portion providing oppo- Serial No. 620,115 (01. 164-17) sitely extending bendable tongues 2, 2 with pointed prong portions 8 extending from the four corners of the base 1. In producing the blanks A, a multiple punch 4 is employed, which as best shown in Fig. 3, provides a plurality of cutting portions 5, 5 each having a cross-sectional area identical with the area of a blank A. It will be noted that the cutting portions 5 of the punch 4 are arranged in spaced relation, with the prong cutting portions 511 separated by a space slightly wider than the tongue cutting portions 51), for a purpose which will shortly appear. A die block 6 for cooperation with the punch 4 provides a series of spaced die openings 7 for receiving the blanks A cut from the stock by operation of the punch As shown in Fig. 1, a strip 8 of sheet metal stock is fed intermittently over the die block 6 for operation upon by the punch 4, and each downward stroke of the punch 4 is adapted to cut from the strip 8 separate blanks A corresponding in number to the cutting portions 5 on the punch. As a result of the first punch stroke, there is formed in the strip 8 a series of openings 9, and in feeding the strip 8 for operation upon by the punch 4, the line of longitudinal movement of the strip 8 is at an angle to a line X-X passing through the centers of the series of blank openings 9. After the first stroke of the punch i, the latter is raised and the strip 8 is fed a distance such that when the punch 4 makes its next downward strokefthe tongue cutting portions 5b of the punch will cut into the areas left in the strip between the prong portions of adjacent openings 9 cut by the preceding punch operation, while the prong cutting portions Sa will cut into the areas of the strip left between the tongue and prong portions of the same opening 9.

The amount that the strip 8 is fed each time is indicated at YY in Fig. 2, and it is evident that each feed is less than the over-all length of the blank. Furthermore, with the amount and direction of strip feed indicated, successive strokes of the punch 4 will result in the formation of interlocking series of blanked openings 9. According to the invention, the interlocking of the blanked openings 9 is such that a prong portion of any given opening in the strip lies partially within a line extending tangentially between the tongue TT of the next adjacent opening 92). Similarly, part of a prong portion of the opening 91), indicated by the horizontal shading, lies within the tangential boundary TT of the opening 9a.

In the production of metallic fastener blanks according to the present invention, the above described interlocking of the blanked areas reduces the strip waste to a minimum, thereby making it possible to manufacture fastener blanks in large quantities at a substantial saving over the previous manufacture of such blanks. While the present invention is shown and described with reference to the production of blanks of a particular form, obviously the method is equally well adapted for the production of other forms of sheet metal blanks having irregular outlines of such character as to permit interlocking of the blanked areas, with portions of one blanked opening lying within the tangential boundaries of adjacent openings.

I claim, 1 1. The improvement in the production of metallic blanks of the type described, which consists in intermittently feeding sheet metal stock for operation upon by a multiple punch with the line of stock feed oblique to the longitudinal axis of a punched blank, successive strokes of the punch resulting in interlocking of the blanked areas in the stock, with a portion of one blanked area lying within the tangential boundary of an adjacent blanked area.

2. The improvement in the production of metallic blanks each having projecting prong and tongue portions of different lengths, which consists in intermittently feeding a strip of sheet metal for operation upon by a punch having a series of spaced cutting portions each having a form corresponding to the form of blank to be produced, the amount and direction of strip feed and the disposition of the said cutting portions of the punch being such that successive punch strokes result in interlocking of the blanked areas of the strip, with a prong portion of one blanked area lying Within a line extending tangentially between prong and tongue portions of an adjacent blanked area.

3. The improvement in the production of metallic blanks of the type described, which consists in intermittently feeding sheet metal stock for operation upon by a multiple punch to cut blanks from said stock, the direction of stock feed being oblique to the longitudinal axis of the blanks as punched, and the disposition of the cutting portions of the punch and the amount of stock feed being such that successive punch strokes result in the cutting of interlocking blanked areas in the stock, with a portion of one blanked area lying within the tangential boundary of an adjacent blanked area.

4. The improvement in the production of metallic blanks of the type described, which consists in intermittently feeding sheet metal stock .for operation upon by a multiple punch to cut blanks from said stock, the direction of stock feed being GEORGE A. ANDERSON. 

